When we think of body builders, many of us envision a person similar to the Hulk, Sylvester Stallone, or Arnold Schwarzenegger. Essentially we visualize a man or woman who is so muscular that we imagine that they can barely turn their head. This stiffness or lack of flexibility is one of the most common myths about heavy weight training. In fact, if weight training is performed correctly, incorporating a full range of motion, heavy weight training can actually enhance your flexibility.
This misconception about weight training leading to inflexibility has remained firmly in people’s minds, despite the fact that studies as long ago as the 1960s proved otherwise. Later studies have confirmed that properly performed strength training exercises serve to increase flexibility rather than reduce it.
A 2002 study published in the Journal of Strength and Conditioning Research evaluated the effect on flexibility of a 10-week resistance training program on a group of 11 elderly female subjects. The control group consisted of eight elderly women who were physically inactive. The women’s level of flexibility was assessed by a sit-and-reach test performed both before and after the 10-week training period. Using resistance machines, the women in the training group performed eight different strength training exercises (seated row, seated biceps curl, seated triceps press, shoulder press, chest press, calf press, abdominal crunch and leg press) without performing any flexibility exercise. The study found that the training group women had achieved an average increase of 13% more flexibility over the control group by the end of the training program.
Another study, published the following year in the same journal, found that flexibility was greater in subjects who used light weights (1-3 pounds) on their wrists and ankles during a 10-week training program than the control group who used no weights while training. They surpassed the control group in five out of ten flexibility measures, including left and right neck rotation, knee flexion and hip extension.
Weight training exercises should involve the full range of motion in order to build strength while maintaining flexibility. To maintain good flexibility while training with weights, learn to vary your workouts so that you do not repeat the same actions over and over. This will encourage your muscles to keep from shortening and becoming less flexible.